I was talking to a guy at my local camera shop that says he is waiting to switch over to digital until sensor quality rises. He says that despite 10-12 megapixels being close to 35mm in quality image-wise, they're having problems with the sensors declining in quality after a few years and requiring more and more light for the same exposure. Is this accurate? I wanted to get some second opinions on it. Just for cost practicality and ease of use I was planning on getting a nice canon sometime in the next few years, but if the thing is only going last around 70-100k exposures, it's really not going to be cost effective at all.